Concentrating photovoltaic (CPV) solar energy systems use reflectors or lenses to focus sunlight on photovoltaic solar cells, which generate electric power. By utilizing a light concentration system, the area of photovoltaic cells can be significantly reduced but still generate the same amount of power relative to a photovoltaic system without light concentration. Since a small amount of photovoltaic cell material is used, then more efficient but more costly photovoltaic cells can be economically used since they are a smaller fraction of the system's total capital cost.
Existing systems may also use single-axis tracking systems where the tracking axis is parallel to the Earth's surface. For sites far from the equator, collector systems with this type of tracking system will concentrate light much more efficiently during the summer than winter because of the significant difference in the sun's path through the sky between the seasons. Therefore, the average daily production in the summer will be much higher than the average daily production in the winter, and therefore producing a very uneven seasonal energy output. The peak hourly output will also be much higher than the annual hourly average. An uneven seasonal energy output results in limitations on system integration. A solar energy system is frequently sized based upon the peak hourly output observed in a typical meteorological year. A solar energy system with an uneven seasonal energy output would therefore deliver less energy throughout the year for a fixed peak versus a system with a more uniform energy output.